Decalcomania and process of making same



Oct. 31, 1961 H. s. BRICKELL DECALCOMANIA AND PROCESS OF MAKING SAMEFiled Aug. 22, 1956 INVEN TOR. HARRY S. BRICKELL.

BY M, M 1.

ATTORNEYS.

United States Patent 3,006,795 DECALCOMANIA AND PROCESS OF MAKING SAMEHarry S. Brickell, Pittsburgh, Pa., assignor to The Metal Decal Company,a corporation of Pennsylvania Filed Aug. 22, 1956, Ser. No. 605,614 2Claims. (Cl. 156-3) This invention is for an improvement in transferpatterns of the type commonly referred to as decalcomania and which aregenerally used for advertising or ornamentation but which, according tothe present invention, may also have other utility, as for exampleprinted electrical circuits or other uses requiring metal foil patterns,and relates to a new transfer print of this character and a method ofmaking the same.

Transfer prints or decalcomania usually comprise a supporting base ofpaper over which is a film of gum or glue, usually a water-softenablefilm, such as dextrine. This coat accepts the printing which issubsequently applied. When the decal is wet, the glue releases theprinted design from the paper so that it may be slipped onto thepermanent base where it is to be displayed. The watersoftenable filmthen constitutes a transfer adhesive which secures the printing to thepermanent base, or other adhesive may be used between the dextrine andthe printmg.

The principal object of the present invention is to provide adecalcomania in which the pattern is comprised of a sheet material suchas metal foil or plastic films whereby ornamental effects of unusualquality can be secured, and by using foil the pattern may compriseornamentation or an electrical circuit. My invention further provides anovel method of making such a transfer pattern.

These and other objects and advantages are secured by my invention whichmay be more fully understood by reference to the accompanying drawings,in which:

FIG. 1 is a schematic view of the first step in the preparation of thedecal;

FIG. 2 is an enlarged schematic View of the three-ply sheet resultingfrom FIG. 1;

FIG. 3 is a view similar to FIG. 1 showing a protective pattern orresist applied over the top sheet or ply of FIG. 2;

FIG. 4 is a diagrammatic view representing the subsequent etching of thefilm except where protected;

FIG. 5 is a schematic view similar to FIG. 2 of the etched product;

FIG. 6 is similar to FIG. 5 but shows a transfer adhesive applied to theresist layer;

FIG. 7 is a view similar to FIG. 6 showing the final lamination; and

FIG. 8 is a plan view of the finished product.

Referring to the drawings, 1 represents a sheet of pliable materialproviding a temporary base. It may be a thin sheet of tissue paperimpregnated with lacquer or latex adhesive. To one surface is applied anadhesive by suitable means, such as a roller-coater A. This adhesive,which may be termed a temporary adhesive, may be a material similar tothat impregnated into the paper, as lacquer or latex adhesive. Theadhesive layer is marked 2. While the adhesive 2 is still fresh andbefore it is set, a film 3, such as metal foil, is brought against itand adhered thereto preferably with pressure, as with pressure rolls B.

The resulting sheet, shown in FIG. 2, then has an impregnated tissuepaper base 1, an adhesive layer 2, and a foil layer 3. FIG. 2 is ofcourse schematic and exaggerated, and does not represent actual relativethicknesses.

A pattern using a resist material is then printed over the exposedsurface of the metal foil, the pattern being the pattern to appear onthe finished product, but in the case of letters would often bereversed. Suitable resists for the purpose are asphaltum, mineral waxes,natural or syntheic resins, and desirably I use as a resist somematerial which may itself be an adhesive. It may be rendered adhesiveeither by slight heat or by the use of a solvent. It is not necessary,however, that the resist be adhesive, and in the ensuing description Ishall specifically describe the use of an additional adhesive. Thepattern printed over the foil with the resist material is designated 4.

The sheet thus prepared is then immersed in a solution, sometimes calleda mordant or etch, which reacts with and etches or dissolves thosesurfaces of the foil not protected by the resist. The base 1 andadhesive 2 of course protect the opposite face of the foil from chemicalattack. For example, with aluminum foil, hydrochloric acid solution isused as a mordant; for coppenperchloride of iron, and for plastic film,a solvent for the plastic. Suitable reactive chemicals or solvents arewell known and per se form no part of my invention. FIG 4 illustratesthis step of etching away the unprotected foil. In this view, C is asimple receptacle containing the mordant into which the composite sheetis put and immersed for the necessary length of time. In some casesagitation increases the rate of etching. When the foil around the resisthas been thus removed the product is washed. The resulting product isshown in FIG. 5. Assuming that the resist is not also an adhesive, anadhesive layer 5 is then applied over the exposed foil, as indicated inFIG. 6. This may be termed the transfer adhesive.

With this adhesive the laminate is then mounted on the decal paper whichis a heavy paper base with a dextrin or other glue or film thercover,preferably water-soluble. In FIG. 7 the laminated body has been turnedupside down with respect to FIG. 6 and mounted on the decal paper. Thepaper itself is designated 6 and the water-soluble film is marked 7.

When thus completed, the original base 1 and temporary adhesive layer 2are stripped away, leaving the reverse face of the foil exposed. Thedecal then has the appearance indicated in FIG. 8, with the exposed foil3, etched to the desired pattern, clean and shining. If the adhesive 2is shellac, alcohol may be used for stripping away layers 1 and 2. Iflatex cement is used, proper pulling should separate layers 1 and 2 fromthe foil. The etched foil pattern is secured to the coated decal papers67 by the adhesive layer 5, and if the resist material 4 is used as thetransfer adhesive, layer 5 may be omitted. If 4 is a thermo-plasticmaterial, slight heat may be used to apply it to the base.

Printed circuits can be prepared in this way with the metal foil givingan assured continuous conducting path. Such a printed circuit may beprepared fiat and then transferred to the base on which it is to beused. If desired it may even be transferred either to the outside orinside of a cylinder, making it possible to place a circuit in a verylimited space, and enabling capacitance to be designed into a circuit,and with other advantages.

In many cases, the exposed surface of the decal may be coated with clearlacquer or varnish to protect the foil.

The decal shown in FIG. 8 is used in the same way as a conventionalprinted decal. The base 6 is wetted, whereby the water soluble gluereleases the design, enabling it to be slipped from the decal paper andadhered to the permanent base by the adhesive 5. Because of the patternor letters being formed of metal foil or other sheet material, unusualdecorative effects are obtained with decals embodying my invention, andin the case of electrical circuits, a much better conducting path can 3be provided than-With usual printing or silk screening procedures.

It is also contemplated that instead of using'a chemical to etch thefoil, electro-chemical processes may be used to remove the area of thefoil not covered by the resist.

Since the pattern-forming or generating foil or plastic sheet isordinarily so thin and flexible that the pattern or letters could not behandled individually, the first supporting sheet and temporary adhesiveprovide body or thickness for handling, as well as providing a resist toprotect one surface of the film during etching. Different colored foilsor films may be used in combination,

and if desired, in succession by repeating the etching step to giveadded attractive value to the pattern or to identify parts of electricalcircuits.

Various changes and modifications may be made from the specificprocedures herein disclosed Within the contemplation of my invention andunder the scope of the following claims.

. I claim:

1. The -method of making a decalcomania transfer in which thedecalcomania pattern is a continuous flexible film which comprises thesteps, in the order named, of

' first releasably adhering a sheet of thin flexible material to onesurface of an etch-resistant supporting flexible film, printinga patternto appear on the decalcomania on the exposed surface of the materialwith an etchprotecting adhesive resist, leaving the remaining area ofthe material exposed, treating the composite sheet s0 prepared with anetching medium to completely remove those portions of the material notso printed upon with the resist, adhering the resist coated surface ofthe material to a Water-soluble glue surface of a decalcomania paper,and then removing the etch-resisting supporting film to expose thatsurface of the etched pattern which was initially adhered to thesupporting film, whereby the resist is then interposed between thepattern and the decalcornania paper.

2. The method of making a decalcornania transfer as defined in claim 1in which the thin flexible material is metal foil.

References Cited in'the file of this patent OTHER REFERENCES PrintedCircuits-Some General Principles and Applications of the Foil Technique;from the Journal of the British Institution of Radio Engineers, vol.XIII, No. 11; November 1953; pages 523541, sections 2.1.1 and 2.6.

1. THE METHOD OF MAKING A DECALCOMANIA TRANSFER IN WHICH THE DECALCOMANIA PATTERN IS A CONTINUOUS FLEXIBLE FILM WHICH COMPRISES THE STEPS, IN THE ORDER NAMED, OF FIRST RELEASABLY ADHERING A SHEET OF THIN FLEXIBLE MATERIAL TO ONE SURFACE OF AN ETCH-RESISTANT SUPPORTING FLEXIBLE FILM, PRINTING A PATTERN TO APPEAR ON THE DECALCOMANIA ON THE EXPOSED SURFACE OF THE MATERIAL WITH AN ETCHPROTECTING ADHESIVE RESIST, LEAVING THE REMAINING AREA OF THE MATERIAL EXPOSED, TREATING THE COMPOSITE SHEET SO PREPARED WITH AN ETCHING MEDIUM TO COMPLETELY REMOVE THOSE PORTIONS OF THE MATERIAL NOT SO PRINTED UPON WITH THE RESIST, ADHERING THE RESIST COATED SURFACE OF THE MATERIAL TO A WATER-SOLUBLE GLUE SURFACE OF A DECALCOMANIA PAPER, AND THEN REMOVING THE ETCH-RESISTING SUPPORTING FILM TO EXPOSE THAT SURFACE OF THE ETCHED PATTERN WHICH WAS INITIALLY ADHERED TO THE SUPPORTING FILM, WHEREBY THE RESIST IS THEN INTERPOSED BETWEEN THE PATTERN AND THE DECALCOMANIA PAPER. 